Quantum Photonics Laboratory, University of Warsaw

SPECTRAL-TEMPORAL ENGINEERING OF QUANTUM LIGHT

We research the potential of spectral-temporal encoding for the processing of quantum information. Our interests include experimental implementations of multidimensional quantum-enhanced metrology. We explore highly efficient, fiber-compatible quantum cryptography protocols. We look for applications of time-energy entanglement.

PHOTONIC INTERFACES FOR QUANTUM NETWORKS

We experimentally investigate methods for coherent modification of spectro-temporal mode structure of optical pulses at the single photon level. We are building highly efficient electro-optic mode converters for single-photon pulses. We explore the properties of highly dispersive optical media.

With our partners within the NLPQT consortium we are involved in building Quantum Key Distribution links in Poland, including and intericty link between Warsaw and Poznań. This activity is enabled by the nationwide academic PIONIER optical fiber network.

QUANTUM TEMPORAL FOURIER OPTICS

We explore applications of the concept of time lens and ultrafast all-optical information processing in the field of quantum optics. We explore new opportunities offered by these techniques for quantum information processing. We address technical challenges associated with applying these concepts to non-classical light.

Publications

Electro-optic frequency shift of single photons from a quantum dot
Sanjay Kapoor, Aleksander Rodek, Michał Mikołajczyk, Jerzy Szuniewicz, Filip Sośnicki, Tomasz Kazimierczuk, Piotr Kossacki, Michał Karpiński
Nanophotonics, https://doi.org/10.1515/nanoph-2024-0550 (2025).
Thanks to a local collaboration with the LUMS lab!

Time-resolved second-order autocorrelation function of parametric downconversion
Dmitri B. Horoshko, Shivang Srivastava, Filip Sośnicki, Michał Mikołajczyk, Michał Karpiński, Benjamin Brecht, Mikhail I. Kolobov
arXiv preprint, arXiv:2502.07691 (2025).
Collaboration within the QuantERA QuICHE project!

Temporal cavities as temporal mode filters for optical information processing
Bakhao Dioum, Shivang Srivastava, Michał Karpiński, Giuseppe Patera
Physical Review A 111, 033704 (2025).
arXiv preprint, arXiv:2303.09155
Collaboration within the QuantERA QuICHE project!

High-dimensional quantum key distribution with resource-efficient detection
Maciej Ogrodnik, Adam Widomski, Dagmar Bruß, Giovanni Chesi, Federico Grasselli, Hermann Kampermann, Chiara Macchiavello, Nathan Walk, Nikolai Wyderka, Michał Karpiński
arXiv preprint, arXiv:2412.16782 (2024).
Thanks to collaboration within the QuantERA QuICHE project!

Quantum key distribution with basis-dependent detection probability
Federico Grasselli, Giovanni Chesi, Nathan Walk, Hermann Kampermann, Adam Widomski, Maciej Ogrodnik, Michał Karpiński, Chiara Macchiavello, Dagmar Bruß, Nikolai Wyderka
Physical Review Applied 23, 044011 (2025).
arXiv preprint, arXiv:2411.19874 (2024).
Thanks to collaboration within the QuantERA QuICHE project!

Efficient detection of multidimensional single-photon time-bin superpositions
Adam Widomski, Maciej Ogrodnik, Michał Karpiński
Optica 11, 926 (2024)
arXiv preprint, arXiv:2308.05523 (2024).

Interface between picosecond and nanosecond quantum light pulses
Filip Sośnicki, Michał Mikołajczyk, Ali Golestani, Michał Karpiński
Nature Photonics 17, 761–766 (2023).
You can view the paper here (for personal non-commercial purposes): https://rdcu.be/dcZPW.
A close-to-the-published-version preprint is available at: https://arxiv.org/abs/2211.05112.
Check out a News&Views summary of our work (by John Donohue) here: https://www.nature.com/articles/s41566-023-01277-y.

Precise on-chip spectral and temporal control of single-photon-level optical pulses
Adam Widomski, Stanisław Stopiński, Krzysztof Anders, Ryszard Piramidowicz, Michał Karpiński
Journal of Lightwave Technology 41, 6255–6262, (2023).

Electro-optic Fourier transform chronometry of pulsed quantum light
Ali Golestani, Alex O. C. Davis, Filip Sośnicki, Michał Mikołajczyk, Nicolas Treps, Michał Karpiński
Physical Review Letters 129, 123605 (2022).
arXiv preprint arXiv:2205.11554
Theory from Paris & Bath, experiment from Warsaw!

Aberration-corrected time aperture of an electro-optic time lens
Sanjay Kapoor, Filip Sośnicki, Michał Karpiński
arXiv preprint, arXiv:2207.07618 (2022).

Control and measurement of quantum light pulses for quantum information science and technology
Michał Karpiński, Alex O. C. Davis, Filip Sośnicki, Valérian Thiel, Brian J. Smith
Advanced Quantum Technologies 4, 2000150 (2021).
Review paper.

Actuator placement optimization for guided waves based structural health monitoring using fibre Bragg grating sensors
Rohan Soman, Kaleeswaran Balasubramaniam, Ali Golestani, Michał Karpiński, Paweł M. Malinowski, Wiesław M. Ostachowicz
Smart Mater. Struct. 30, 125011 (2021).

Aperiodic electro-optic time lens for spectral manipulation of single-photon pulses
Filip Sośnicki, Michał Mikołajczyk, Ali Golestani, Michał Karpiński
Applied Physics Letters 116, 234003 (2020) (featured article).
arXiv preprint arXiv:2004.07195 (2020).

Pure single photons from scalable frequency multiplexing
T. Hiemstra, T. F. Parker, P. Humphreys, J. Tiedau, M. Beck, M. Karpiński, B. J. Smith, A. Eckstein, W. S. Kolthammer, I. A. Walmsley
Phys. Rev. Applied 14, 014052 (2020),
arXiv preprint arXiv:1907.10355 (2020).

A two-step guided waves based damage localization technique using optical fiber sensors
Rohan Soman, Kaleeswaran Balasubramaniam, Ali Golestani, Michał Karpiński, Paweł Malinowski
Sensors 20, 5804 (2020).

Shaking the phase of light
Michał Karpiński
Nature Photonics 13, 306–308 (2019).
News&Views on the recent work from the group of H. X. Tang @ Yale.

Large-scale spectral bandwidth compression by complex electro-optic temporal phase modulation
Filip Sośnicki, Michał Karpiński
Optics Express 26, 31307–31316 (2018).

Measuring the single-photon temporal-spectral wave function
Alex O. C. Davis, Valérian Thiel, Michał Karpiński, Brian J. Smith
Physical Rev. Lett. 121, 083602 (2018).
arXiv:1709.05248.

Experimental single-photon pulse characterization by electro-optic shearing interferometry
Alex O. C. Davis, Valérian Thiel, Michał Karpiński, Brian J. Smith
Phys. Rev. A. 98, 023840 (2018).
arXiv:1802.07208.

Engineering the spectral and temporal properties of a GHz-bandwidth heralded single-photon source interfaced with an on-demand, broadband quantum memory
Patrick S. Michelberger, Michał Karpiński, Ian A. Walmsley, Joshua Nunn
Journal of Modern Optics 65, 1668–1679 (2018).

Entanglement swapping for generation of heralded time-frequency-entangled photon pairs
Dashiell L. P. Vitullo, Michael G. Raymer, Brian J. Smith, Michał Karpiński, Lasse Mejling, Karsten Rottwitt
Phys. Rev. A 98, 026836 (2018).
arXiv:1802.00110.

Measurement of radio-frequency temporal phase modulation with chirped optical pulses
Michał Jachura, Jan Szczepanek, Wojciech Wasilewski, Michał Karpiński
Journal of Modern Optics 65, 262–267 (2018).
arXiv:1706.09881.

Bandwidth manipulation of quantum light by an electro-optic time lens
Michał Karpiński, Michał Jachura (equal contribution), Laura J. Wright, Brian J. Smith
Nature Photonics 11, 53 (2017).
arXiv:1604.02459
See also our press release!

Pulsed single-photon spectrograph by frequency-to-time mapping using chirped fiber Bragg gratings
Alex O. C. Davis, Paul M. Saulnier, Michał Karpiński, Brian J. Smith
Optics Express 25, 12804–12811 (2017).
Selected for Spotlight on Optics! Here’s a brief summary of our paper!

Spectral shearing of quantum light pulses by electro-optic phase modulation
Laura J. Wright, Michał Karpiński, Christoph Söller, Brian J. Smith
Physical Review Letters 118, 023601 (2017).
arXiv:1605.00640 (2016).

Quantum mechanical which-way experiment with an internal degree of freedom
Konrad Banaszek, Paweł Horodecki, Michał Karpiński, Czesław Radzewicz
Nature Communications 4, 2594 (2013).
See also our press release!

Who we are

We are a young dynamic group within the Optics Division of the Faculty of Physics (FUW) at the University of Warsaw (UW). FUW is a world-class physics research centre covering a broad area of physics and is the leading physics research institution in Poland. It hosts numerous groups both in optics (Ultrafast Phenomena Lab, Quantum Memories Lab, Photonic Nanostructures Facility, Information Optics Lab, Cold Atoms, Femtosecond Spectroscopy) as well as quantum information, quantum metrology, and communications theory. This gives us an ideal setting for our research. Interested in joining us? Please check the Jobs section below!

Our Lab

We work in a state-of-the-art optical lab furnished with cutting-edge equipment. This includes a stable ultra-wide-band (up to 35 GHz) arbitrary electro-optic phase modulation setup, an aperiodic time lens, custom dispersive media (thanks to collaboration with ORC in Southampton, UK), low timing jitter superconducting single-photon-counting detectors, telecom and 1.7 – 2.1 um femtosecond pulsed lasers, photon pair sources and a complex optical spectrum analyser for spectrum and spectral phase measurements. We appreciate the initial support of Konrad Banaszek, Czesław Radzewicz and numerous funding programmes (Horizon Europe, EU Structural Funds, National Science Centre of Poland – NCN). Our current funding includes a SONATA-BIS project from NCN, an international OPUS-LAP project with the University of Innsbruck, Austria, funded by the NCN and the Austrian FWF funding agency, as well as a Horizon Europe project on Mid-Infrared Quantum Sensing and Technologies (MIRAQLS).

We are also part of the National Laboratory for Photonics and Quantum technologies – NLPQT infrastructural project, which funded our recent equipment purchases. We have recently completed a QuantERA grant (together with groups in Germany, Italy, France & UK) and a major project funded by the Foundation for Polish Science (FNP) First Team programme – please click here for more details! Earlier we completed another FNP project – please click here for details.

Main Team

Michał Karpiński

Team leader

Michał Mikołajczyk

PhD Student

Adam Widomski

PhD Student

Sanjay Kapoor

PhD Student

Jerzy Szuniewicz

PhD Student

Maciej Ogrodnik

PhD student

Jan Krzyżanowski

PhD student

Adam Świniarski

Masters student

Ksawery Mielczarek

Masters student

Natalia Bednarek

Masters student

Alumni

Maciek Gałka

MSc student at QPL,
obtained his PhD at University of Cambridge, UK

Dominika Bondar

BSc student at QPL. Got a job at Fluence.technology after MSc graduation.

Arifah Nurul Amaliah

MSc student at QPL.
Got a job at Vigo Photonics after graduation.

Dinara Kalkabaeva

MSc student at QPL,
got a job at OPmobility

Filip Sośnicki

Got his PhD at QPL.
Postdoc at the Insitute for Photonic Quantum Systems at Paderborn University, Germany.

Ali Golestani

Got his PhD at QPL.
Postdoc at Department of Electrical and Computer Engineering, University of Toronto

Summer students

Prashant Dagale

Summer of 2018

Martin Luttmann

Summer of 2018

Monika Mikulicz

Summer of 2018

Jadwiga Wilkens

Summer of 2019, financed by DAAD

Lyudmila Silantieva

Autumn of 2020, financed by BARI - Baltic Science Network

Cedric Hannemann

Summer of 2021

Karol Piotrowski

Summer of 2023, financed by Candela Fundation

Doğukan Taş

Summer of 2023

Jobs

We are currently looking for:

• 2 PhD students for our SONATA-BIS project on high-dimensional entanglement in integrated photonic structures. The PhD positions are fully funded for up to 4 years. Please apply by e-mail until 14 May 2025 following the instructions in the SONATA-BIS PhD student official announcement
• 1 PhD student for our international TSI-PHY project in collaboration with the University of Innsbruck, Austria, 12 months with extension possibility. Please apply by e-mail until 14 May 2025 following the instructions in the TSI-PHY PhD student official announcement
• 1 post-doc for the SONATA-BIS project on high-dimensional entanglement in integrated photonic structures, up to 36 months. Please apply by e-mail until 31 May 2025 following the instructions in the post-doc official announcement.
• You are encouraged to informally contact Dr Michał Karpiński by e-mail before submitting a formal application to any of the positions listed above.

We are constantly looking for ambitious Postdocs, PhD, MSc and BSc students. Below you will find information about any open positions in our externally funded projects. You can also join our group by coming with your own funding, or enrolling for the MSc or PhD programmes at the University of Warsaw. Please check our coming with your own funding website for more details.

In particular:

• the next regular application round for our funded PhD programme will be in May & June 2025.
• recruitment for the English-language MSc programmes in Optics or Quantum Physics and Chemistry wiil be open in June 2025.

Find us